hydro foil?

[bigcountry5585]

I have a 1448 flat bottom jon boat with a 35 evinrude tiller handle motor. Will a hydro foil do any good on it? What do they do?

 

[steelespike]

Re: hydro foil?

They mostly help the boat to plane quicker it also may make the boat bound around less.It may stay on plane easier at reduced throttle.
They may cost some top end. Usually I describe them as a bandaid over a poor setup.
Some times you gotta do it.
A 14/48 with a 35 should get up and scoot. Do you have any problem with it?

 

[Nuaticocat]

Re: hydro foil?

I had a 14 foot fisher with a 25 merc. Took a while to get on plane and was scary as hell at top speed. I added a hydrofoil and it popped right up and was very stable on plane. night and day. It creates lift on the stern. Stern up, bow down. Went from 10 percent of the boat in the water to 40 percent in the water. As stated, it is a fix for an unbalanced boat. I made mine out of some sheet aluminum 1/8 thick.

 

[bigcountry5585]

Re: hydro foil?

have an old 1978 Lowe 1448 flat bottom jon boat with a 1976 Evinrude 35 tiller handle motor. Its a short shaft motor. I weigh 360 lbs, 6 gallons of fuel, and a battery in the back of the boat. When I first put the motor on this boat, I put the tilt pin in the first hole closest to the boat so I wouldn't flip.it over. I ran full throttle for miles on the river and it did fine but felt like it was dragging something behind it and the bow was plowing into the water. A couple weeks later I put it on a smaller river and decided to put the pin in the second hole hoping it would raise the bow but it really didn't. The problem is that when I was at 3/4 throttle it did fine, but when I increased to full throttle the boat would suddenly stop, and veer hard to the left. The cavitation plate is approximately 1/2"-3/4" above the bottom of the boat. Is it possible to get the boat to ride more on the stern instead of plowing down in the front.

 

[JimS123]

Re: hydro foil?

A DoelFin hydrofoil shines best in a tiller boat with battery and gas tank aft. The more weight aft and the more it becomes necessary. With the stern being forced up, with n o other changes it usually keeps the bow down. Thus, the foil also provides the ability to tilt the motor further out to raise the bow back up.

Many say they lose speed. I have limited experience with the foil. I've only been using them for about 30 years and have had them on 6 different boats, 4 of which we currently still have. In every case we got MORE speed.

Another positive about foils is that they make an underpowered boat perform better. That's where I would be cautious in your case. A 35 on a 1445 jon seems a bit much. I would be careful at wot - it might get a bit squirrely.

 

[steelespike]

Re: hydro foil?

From your description I don't think a foil is your solution.
What do you mean stop?Did the motor just stop or did the boat seem to dive into the water?
Is the bottom clean and smooth no dents or damage near the transom?

 

[steelespike]

Re: hydro foil?

From your description I don't think a foil is your solution.
What do you mean stop?Did the motor just stop or did the boat seem to dive into the water?
Is the bottom clean and smooth no dents or damage near the transom?

 

[redneck joe]

Re: hydro foil?

sounds like it might need a long shaft?

 

[bigcountry5585]

Re: hydro foil?

At 3/4 throttle the boat does fine, but the bow plows down bad. At full throttle the boat suddenly comes to a stop with the motor still running wide open and abruptly veers to the left and stops. It doesnt do this when the motor is all the way down (closest to transom) but it does it in the second hole from the transom. I would think with the motor, me (360 lbs), a battery, and six gallons of fuel that the bow would be up, not plowing. The motor runs excellent to be a 1976. With the pin in the second hole from transom it takes a few seconds (5-7) for the bow to come down, and during that time I can't see squat. I'm guessing if I move the pin further out that the bow might come down but I'm scared I might flip it over on me. I'm going to eventually invest in a side or center console or stick steer, but right now I can't afford it. I mainly just set bush hooks for cats on the Big Pee Dee river here in Florence County SC. I love this boat because its very wide at the top and stable with my big a** in it. I just want to be able to get the bow up and run full throttle. I do take my wife and three year old from time to time, and want it to be safe when they are in it. I ran it hot a couple weeks ago and have my motor man replacing the water.pump housing and impelled right now. I asked him yesterday if the motor is too high and he said it was fine. Sigh....HELP!

 

[steelespike]

Re: hydro foil?

The bow is so low it is bow steering.
Check the bottom for damage or a hook near the transom. Use a straight edge parallel to the keel to see if the bottom is straight.
Is the motor the right length.The plate just above the prop should be about even with the bottom.
Is the transom weak allowing the motor to flex?

 

[Nuaticocat]

Re: hydro foil?

The anti cav plate should be even with the bottom of the boat. It sounds like you are not moving water effieciently. I would drop the motor down 3/4 inch and run the pin as close to the boat as possible. If the boat stops with the motor running flat out, the prop isn't moving water. Either the prop is being shrouded at speed by the waveform or the prop isn't turning. Drop the motor down until the bow rides high until plane.

 

[JimS123]

Re: hydro foil?

I had a similar problem. The DoelFin solved the low end problem, but I could never safely run above 3/4 throttle without bow steering. On that boat the problem was with a 25. When I switched to an 18 the problem went away. I acytually improved the top speed because now i could go wot.

Your boat is overpowered with too much weight aft.

 

[bigcountry5585]

Re: hydro foil?

I also forgot to mention that the bow bounces up and down.

 

[bigcountry5585]

Re: hydro foil?

Its also very, very hard to steer.

 

[steelespike]

Re: hydro foil?

Do you mean physically difficult (hard) to steer or difficult to steer accurately?
Have you checked any of the things I suggested?

 

[Mi duckdown]

Re: hydro foil?

Pics are worth a thousand words.